1. Field of the Invention
The invention relates to a disc music box for playing a melody by driving to rotate a music box disc having a plurality of play engaging parts in a predetermined play pattern by a motor, rotating star wheels by the play engaging parts engaged at a predetermined play timing, and plucking music box petals by the star wheels to play the melody.
2. Description of the Related Art
Generally known sounding means used for a time signal of a timepiece or the like is not limited to one which produces an inorganic electronic sound by a sounding circuit and a loud speaker, but also includes one which produces a conventional soft music box's sound by a mechanical music box instrument.
Such a music box instrument generally plays a predetermined music number and comprises sounding prongs in a strip shape with a plurality of sounding parts corresponding to the musical intervals, a barrel which is disposed to oppose the sounding prongs and provided with pins protruded to pluck the sounding parts of the sounding prongs with predetermined playing timing, and a drive unit for rotating the barrel at a predetermined speed.
Specifically, the sounding prongs have a substantially oblong metal plate formed in the shape of comb teeth which have the sounding parts corresponding to the number of musical intervals, and these comb teeth (music box petals) have a predetermined length and thickness to have specific pitches to make allotted music box sounds when the tips of the music box petals are plucked. The barrel is formed in a cylinder longer than at least the sounding prongs, disposed to be rotatable and to face the sounding parts of the sounding prongs, and formed intermittent pins corresponding to a music number and protruded from the outer periphery of the barrel which is opposed to the sounding parts of the sounding prongs. And, the drive unit drives to rotate the barrel in a predetermined direction at a given speed, and the respective pins of the barrel pluck the respective sounding parts of the sounding prongs with predetermined timing to play a music number.
Another music box instrument has been proposed which is provided instead of the barrel with a circular plate-shaped music box disc having the pattern of a predetermined music number, and designed so that the music box disc can be changed to play a desired music number.
This music box disc is a circular plate, its one side is divided into a plurality of tracks corresponding to the music box petals of the music prongs, and the engaging and driving units are formed at a position in a circumferential direction corresponding to the playing timing of musical intervals allotted by the tracks. These engaging and driving parts comprise pins protruded from one side of the music box disc or holes having a predetermined diameter. And, the predetermined parts of the sounding prongs are plucked by these engaging and driving parts to play a music box.
A music box having the music box disc includes a circular plate-shaped music box disc having multiple engaging and driving parts to play music, the music box disc is driven to rotate by a drive mechanism of the music box body. And, the music box body has star wheels for plucking the music box petals of the sounding prongs mounted to be rotatable on a star wheel shaft. And, when the music box disc is rotated by the drive mechanism, the engaging and driving parts of the music box disc engage with picks of the star wheels which correspond to the engaging and driving parts to rotate the star wheels, and the music box petals are plucked by other picks which are subsequent to the rotating star wheels to produce music box sounds to play a melody.
This disc music box holds the music box disc at a position opposed to the star wheels by pushing from one side by a music box disc holding arm which is provided with a holding roller, so that a relatively thin music box disc can be used. Therefore, music box discs having different patterned music numbers formed can be produced in a large number inexpensively, stored and managed easily because they are thin, and transported efficiently.
In addition, since the music box discs are handled with ease, they can be attached to or removed from the music box readily and exchanged in a short time. Therefore, when a plurality of music box discs for different music numbers are provided in advance and a music box disc is changed to another disc for a desired music number, a music number to be played can be changed quickly and with ease.
As described above, the disc music box is easy to mount a desired music box disc by selecting from a plurality of music box discs as compared with the music box provided with a stationary barrel for a single music only. It has an advantage that music numbers can be changed flexibly and easily.
As described above, this music box holds the music box disc positioned to oppose the star wheels by pressing from its one surface by a music box disc holding arm which has a holding roller, so that it is advantageous to use a relatively thin music box disc. On the other hand, a drive roller is disposed on a part of the holding roller of the music box disc holding arm to rotate the music box disc by the music box disc holding arm. Therefore, there are still disadvantages to be solved that the rotation drive mechanism is simplified and the rotation drive is performed with certainty.
Besides, the above-described disc music box does not have a satisfactory mechanism of positioning to start rotating the music box disc and of the stopping structure after one rotation of the music box disc.